comparison mercurial/phases.py @ 51516:e0f92bd98c24 stable

phases: avoid a potentially costly dictionary interation in some case

If we retract for the draft phase, there is not non-public item to be retracted
and we can skip this part. This part is was apparently super costly thanks to
Python.

On mozilla-try-2019-02-18, a perf::unbundle call with a 10 000 changesets
bundle gives give use the following timing.

e57d4b868a3e:     4.6 seconds
ac1c75188440:   102.5 seconds
this-changeset:  30.0 seconds

So we recovered about ⅔ of the regression, the next changeset will give us the
rest back.

51514:394ea4428163

                        changed_revs[r] = r_phase
                    elif r in currentroots:
                        replaced_roots.add(r)
            sets = self._phasesets
            sets[targetphase].update(changed_revs)
            for r, old in changed_revs.items():
                if old > public:
                    sets[old].discard(r)

        if new_roots:
            assert changed_revs

            final_roots = new_roots | currentroots - replaced_roots

51516:e0f92bd98c24

                        changed_revs[r] = r_phase
                    elif r in currentroots:
                        replaced_roots.add(r)
            sets = self._phasesets
            sets[targetphase].update(changed_revs)
            if targetphase > draft:
                for r, old in changed_revs.items():
                    if old > public:
                        sets[old].discard(r)

        if new_roots:
            assert changed_revs

            final_roots = new_roots | currentroots - replaced_roots